Door-spring



UNITED sTATEs PATENT EEicE.

A. WESTCOTT, OF SYRACUSE, NEW YORK.

DOOR-SPRING.

Specification of Letters Patent No. 7,692, dated October 1, 1850.

To all whom t may concern:

Be it known that I, A. l/VEsTcoTT, of Syracuse, in the county ofOnondaga and State of New York, have invented a new and usefulImprovement in Door-Springs, of which the following` is a full, clear,and exact description, reference being had to the accompanying drawing,which forms part of this specification and represents a view 1nperspective of a door and door-frame with my spring applied thereto.

In my improved spring the door is connected by a strap with the movingextremity of a jointed lever, whose opposite extremity is free to turnon a pivot and is acted upon by a spiral spring which tends tostraighten the lever whenever it is flexed by the opening of the door.lThe movable extremity of the jointed lever is fitted with a groovedwheel which runs upon a track of such peculiar form that within adetermined limit it will not prevent the spring from closing the door,but when the door is opened beyond this limit the track counteracts thetendency of the spring and thus allows the door to stand open. In theaccompanying drawing the spring, lever, and track are made fast to aframe A which is screwed to the lintle B o-f the door. The jointed leverC is pivoted at the extremity nearer the hinge post D of the door frame,to the spring frame A, and its opposite extremity, or that nearer thelockpost E, is fitted with a friction wheel a which runs upon a track F,whose general direction is parallel with that of the lintle B. The rimof this friction wheel is grooved to guide it along the track which ittraverses. An arm b projects from the hinged extremity of the lever C,and its upper end is secured to the movable end of a spiral spring Gwhose opposite en'd is made fast to the frame A. The movable extremityof the jointed lever is connected by a strap c with a bent standard I-Iprojected upwards from the upper edge of the door. This strap runs uponan upright friction roller (l at the hinge-post end of the frame.

It will be perceived from the foregoing description that if the track Fon which the friction wheel runs is level, the spring will shut to thedoor from any position to which it may be opened, provided itis notopened so far as to throw the extremity of the standard on the doorbehind a line drawn through the hinges of the door and the point on thelever at which the strap is attached, in which case the spring wouldkeep the door open. In my improved door spring the upper edge of thetrack, instead of being level, is curved, as represented in the drawing,a portion of its surface being raised as at e. By this device thedescending inclination on the lock post side of the highest part c ofthe track will facilitate the action of the spring in closing the door,provided the door be not opened far enough to draw the friction wheel apast the rise. The descending inclination on the hingeepost side of theraised part e of the track counteracts the action of the spring andprevents it from shutting the door whenever the latter is opened so farthat the friction wheel is drawn over the rise. The curve of thisportion of the track is such that it will oppose enough resistance tothe motion of the friction wheel to cause it to remain stationary in anyposition in which it is placed by the opening of the door, hence thelatter will stand open, whenever it is in such a position as to bringthe friction wheel upon this portion of the track.

In constructing these door springs for sale it will generally beexpedient to construct the curved track in a single piece, but in somecases it may be well to make the raised part separate from the rest, insuch. manner that it can be slipped from one end of the track to theother, thus enabling the user to change the limit within which the doorwill close under the action of the spring. Another convenient manner ofattaining this end will be by constructing the track much longer thanthe frame to which it is secured, and arranging it to slide to and froin slots in which it can be made fast by a clampscrew, it can then beslid to and fro to set the raised portion in any required position.

That I claim as my invention and desire to secure by Letters Patent is-The door spring consisting essentially of a spring, jointed lever, strapand curved track, the latter being of the form herein described tocontrol the action of the spring and the several parts together with thedoor and door-frame being arranged with respect to each othersubstantially as herein described.

In testimony whereof I have hereunto subscribed my name.

AMOS WESTCOTT.

Witnesses:

I. N. BABCOCK, M. E. WHITE.

